Process for improving production of Fischer-Tropsch distillate fuels
Abstract
Olefins and alcohols present in Fischer-Tropsch light naphthas are converted to dialkyl ethers of the formula: R—O—R′ where R and R′ are each primarily non-tertiary alkyl groups of more than four carbon atoms, via hydration of the olefins to alcohols followed by dehydration of the alcohols. Ethers may also form by direct reaction of olefins and alcohols. The ethers are separated from the remaining paraffins in the naphtha by distillation and added in an amount of 1-25 wt. % to paraffinic mid-distillate fuel components obtained by hydrotreating a Fischer-Tropsch product. The properties of the distillate fuel components such as lubricity and seal swell are improved by the dialkyl ethers. The removal of olefins and alcohols from the naphthas reduces refining and lead to a more salable product.
Claims
exact text as granted — not AI-modified1 - 15 . (Canceled)
16 . A distillate fuel component having the following properties:
(a) cetane number >55; (b) sulfur content <15 ppm by weight; (c) polycyclic aromatic content <1.5 wt. %; and (d) a concentration of ethers greater than 1 wt. %, wherein the ethers are of the formula R—O—R′, wherein R and R′ are each primarily non-tertiary alkyl groups of at least four carbon atoms.
17 . A distillate fuel component according to claim 16 , wherein the concentration of ethers is >5 wt %.
18 . A distillate fuel component according to claim 16 , wherein the concentration of ethers is >10 wt %.
19 . A distillate fuel component according to claim 16 , further having a nitrogen content <10 ppm by weight.
20 . A distillate fuel component according to claim 16 , further having a pour point of <−12° C. and a cloud point of <−10° C.
21 . A distillate fuel component according to claim 16 , further having an initial boiling point of >350° F.
22 . (Canceled)
23 . A distillate fuel component according to claim 16 , wherein the distillate fuel component is a diesel fuel.
24 . A distillate fuel component according to claim 16 , further having <15 volume percent aromatics.
25 . A distillate fuel component according to claim 16 , wherein the distillate fuel component is derived from a Fischer-Tropsch process.
26 . A distillate fuel according to claim 23 , wherein the fuel meets all specifications as described in ASTM D975 for a low sulfur no. 2-D fuel.
27 . A distillate fuel component according to claim 16 , wherein the distillate fuel component comprises greater than 70% by weight isoparaffins.
28 . A distillate fuel component according to claim 16 , wherein the distillate fuel component boils in a range of about 250° F. to about 700° F. as measured by the 5% and 95% points.
29 . A distillate fuel component according to claim 16 , wherein R and R′ are alkly groups of at least four carbon atoms with less than 10% being tertiary alkyl.
30 . A distillate fuel component according to claim 16 , wherein R and R′ are alkly groups of at least four carbon atoms with less than 5% being tertiary alkyl.
31 . A distillate fuel component according to claim 16 , wherein R and R′ are alkly groups of at least four carbon atoms with less than 2% being tertiary alkyl.
32 . A distillate fuel component according to claim 16 , further comprising an additive selected from the group consisting of antioxidants, detergents, dispersants, and mixtures thereof.
33 . A distillate fuel component according to claim 16 , further comprising an additive selected from the group consisting of antioxidants, detergents, dispersants, and mixtures thereof.
34 . A distillate fuel component according to claim 16 , further comprising a sulfur-containing petroleum-derived feedstock.Join the waitlist — get patent alerts
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